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United States Patent |
5,302,147
|
Oishi
|
April 12, 1994
|
Cowling assembly for a marine propulsion engine
Abstract
A unitary cowling assembly for covering a fore-to-aft extending marine
propulsion engine comprising a front cowling section adapted to extend
around a front portion of the marine propulsion engine and a rear cowling
section adapted to be fixedly connected to the front cowling section and
to extend around a rear portion of the marine propulsion engine is
disclosed. By extending the front and rear cowling sections fore and aft
of the engine and interconnecting the cowling sections along a stiffened
joint that extends laterally across the engine, the top surface and the
side surfaces of the cowling, which are subjected to the highest
vibrational loads from operation of the marine engine, can be structurally
reinforced so as to inhibit such vibrations and the associated noise,
while still providing an easily moldable cowling assembly.
Inventors:
|
Oishi; Hiroshi (Hamamatsu, JP)
|
Assignee:
|
Sanshin Industries, Co., Ltd. ()
|
Appl. No.:
|
949132 |
Filed:
|
September 23, 1992 |
Foreign Application Priority Data
Current U.S. Class: |
440/77 |
Intern'l Class: |
B63H 021/36 |
Field of Search: |
440/77,900,76,78
|
References Cited
U.S. Patent Documents
2224900 | Dec., 1940 | Conover | 440/77.
|
3955526 | May., 1976 | Kusch | 440/77.
|
4571193 | Feb., 1986 | Takada et al. | 440/77.
|
4869693 | Sep., 1989 | Curtis et al.
| |
5052961 | Oct., 1991 | Uchida et al. | 440/77.
|
5064393 | Nov., 1991 | Inoue | 440/77.
|
Foreign Patent Documents |
2-151594 | Jun., 1990 | JP.
| |
Primary Examiner: Huppert; Michael S.
Assistant Examiner: Brahan; Thomas J.
Attorney, Agent or Firm: Bacon & Thomas
Claims
I claim:
1. A cowling assembly for covering a fore-to-aft extending marine
propulsion engine comprising:
a front cowling section having a front wall, a top wall and sidewalls
adapted to extend around a front portion of a marine propulsion engine;
a rear cowling section having a rear wall, a top wall and a sidewalls
adapted to extend around a rear portion of a marine propulsion engine; and
means for permanently, fixedly connecting said front and rear cowling
sections along a continuous joint extending laterally across the top wall
and sidewalls thereof to form a unitary cowling member, said joint having
an associated thickness which is greater than the adjacent thickness of
the top walls and sidewalls of the front and rear cowling sections such
that said cowling assembly is stiffer in resisting deflection at the top
wall and sidewalls which are subject to the greatest stresses and strains
created by vibrations developed during operation of a marine propulsion
engine.
2. A cowling assembly is claimed in claim 1, wherein said connecting means
comprises an adhesive.
3. A cowling assembly as claimed in claim 1, wherein said connecting means
comprises a fastener.
4. A cowling assembly as claimed in claim 1, wherein said unitary cowling
member comprises an upper cowling member, composed of said front and rear
cowling sections, which is adapted to be removably secured to a lower
cowling member of said cowling assembly.
5. A cowling assembly as claimed in claim 1, wherein each of said front and
rear cowling sections are provided with at least one internal
reinforcement rib.
6. A cowling assembly as claimed in claim 4, wherein the at least one
internal reinforcement rib on each of said front and rear cowling sections
extends generally horizontally and is located on said sidewalls, spaced
from said top walls thereof.
7. A cowling assembly as claimed in claim 1, wherein one of said front and
rear cowling sections terminates at said joint in a bifurcated portion and
the other of said cowling sections terminates at said joint in the form of
a tongue, said tongue extending into said bifurcated section to form said
joint.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to a cowling assembly for a marine
propulsion engine and, more specifically, to a cowling assembly formed
from two or more fore-to-aft extending sections which are fixedly
connected to form a unitary cowling member.
2. Description of the Prior Art
It is widely known in the marine art to cover a propulsion engine with a
cowling. Since such cowlings often need to be manually removed to gain
access to the engines, it is desirable to minimize the weight of the
cowling. To achieve this minimal weighing, it has been proposed to mold
such cowlings from plastic or other lightweight materials. In order for
the cowling to have sufficient strength and in order to avoid noise
problems associated with vibrations developed during running of the marine
engine, prior art cowlings have been made relatively thick which
undesirably increases the weight of the cowling.
As exemplified by U.S. Pat. No. 4,869,693, it has heretobefore been
proposed to form an upper cowling member from two parts which are divided
in the lengthwise direction so as to form right and left halves which are
permanently joined together. Constructing the cowling from two halves
takes advantage of known mold manufacturing processes resulting in reduced
costs. Unfortunately, although such a cowling formed from left and right
halves which are joined together increases the strength of the top of the
cowling, the left and right sides remain low in strength.
Due to the inherent vibrations developed during operation of a marine
engine, the left and right sides of the cowling, as well as the top, are
subject to the greatest vibrational fatigue stress and strains. Therefore,
although the prior art teaches providing a cowling formed from two parts
which are secured together in the lengthwise direction so as to increase
the strength of the top of the cowling, such prior art does not provide
for increasing the strength of the left and right sides of the cowling and
therefore there is a need in the art for a cowling assembly which can
inhibit vibrations on not only the top of the cowling but also the left
and right sides as well.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a cowling assembly for
covering a fore and aft extending marine propulsion engine which provides
for increased strength of the cowling top as well as both the left and
right sides so as to inhibit vibrations of the cowling during operation of
the engine.
It is a further object of the present invention to provide a structurally
sound, yet lightweight cowling assembly for covering a marine propulsion
engine which can be readily manufactured by known molding processes.
These and other objects of the present invention are accomplished by
providing a unitary cowling assembly for covering a fore and aft extending
marine propulsion engine wherein the cowling assembly comprises a front
cowling section adapted to extend around a front portion of a marine
propulsion engine and a rear cowling section adapted to extend around a
rear portion of the marine propulsion engine. The front and rear sections
of a cowling assembly constructed in this manner are joined from a left
surface portion, across a top portion and along a right surface portion
such that the strength of the top, left and right sides of the cowling is
increased, thereby inhibiting vibrations on these surfaces and reducing
noise that would result from their vibration.
Additional objects, features and advantages of the present invention will
become more readily apparent from the following detailed description of
preferred embodiments thereof, when taken in conjunction with the drawings
wherein like reference numerals refer to corresponding parts in the
several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a side view of an outboard marine engine equipped with the
cowling assembly of the present invention.
FIG. 2 is a top, partial cross-sectional view of the cowling assembly of
FIG. 1.
FIG. 3 is an exploded cross-sectional side view of a portion of the cowling
assembly shown in FIG. 1.
FIG. 4 is an enlarged cross-sectional side view of an attachment area
between upper and lower cowling units.
FIG. 5 is a partial cross-sectional view depicting the connection between
the front and rear cowling sections of the present invention according to
a second embodiment thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With initial reference to FIG. 1, an outboard marine engine is generally
indicated at 10 and includes a propulsion unit 12 which is pivotally
mounted about a tilt pin 13 to a stern plate or transom 14 of a
watercraft. Propulsion unit 12 can also be steered by means of a steering
bracket 15. Tilt pin 13 is formed as part of a clamp bracket 16 and
steering bracket 15 is formed part of a swivel bracket 18 which functions
to pivotally and steerably attach propulsion unit 12 to transom 14 in a
manner known in the art. As also known in the art, propulsion unit 12 is
driven by an engine 20 secured thereabove. Engine 20 is adapted to be
covered by a cowling assembly as will be described in detail below with
initial reference to FIGS. 1 and 2.
As depicted, the cowling assembly includes an upper cowling member 24 which
is comprised of a front cowling section 24A and a rear cowling section
24B. Front cowling section 24A extends around a front portion of marine
propulsion engine 20 and rear cowling section 24B extends around a rear
portion of marine propulsion engine 20. Front and rear cowling sections
24A, 24B are adapted to be fixedly secured together to form a unitary
upper cowling member 24. According to the preferred embodiment, front and
rear cowling sections 24A, 24B are joined by bifurcating the rear end (not
labeled) of front cowling section 24A so as to form a groove 30. The front
end (not labeled) of rear cowling section 24B is provided with a tongue 32
which is adapted to project into groove 30 and to be adhesively bonded
therein as depicted in FIGS. 1 and 2. By using an adhesive, front cowling
section 24A and rear cowling section 24B can be fixedly secured together
about a joint line indicated at 25.
By this arrangement, the junction between front cowling section 24A and
rear cowling section 24B, generally indicated at 40, increases the
thickness and thereby the resistance to deflection of unitary cowling
member 24 along the joint as compared with the adjacent top sidewall 42 as
well as left and right sidewalls 44. Therefore, the strength of the top
and the left and right sidewalls 42,44 of unitary cowling member 24 is
increased where needed in order to minimize vibrations on the these
surfaces and reduce the noise resulting from operational vibration.
Obviously, this junction area 40 is thicker and heavier than a cowling
with no such junction and is actually shorter in length than the junction
associated with the prior art as discussed above which extends lengthwise
on the cowling. This shorter junction length also functions to prevent an
unnecessary weight increase of upper cowling member 24 so as to permit
upper cowling member 24 to be readily, manually removed from lower cowling
member 22 when desired. This shorter junction length also decreases the
amount of adhesive necessary to join the two cowling sections 24A and 24B.
Further in accordance with the present invention, a horizontally extending
rib 34 is provided on the inside of upper cowling member 24, generally
intermediate the point between top sidewall 42 and the connection of upper
cowling member 24 with lower cowling member 22. Ribs 34 functions to
increase the wall thickness in a predetermined portion of the upper
cowling member 24 so as to further improve the strength of the left and
right sidewalls 44 as well as front wall 45 and rear wall 47. In practice,
it has been found that ribs 34 provide sufficient increased strength to
front and rear walls 45 and 47 since these surfaces have less area and are
not as prone to the inherent vibrations developed during operation of
engine 20. Depending upon the size of engine 20, a larger cowling may be
required and it is possible to increase the size and/or number of ribs 34
accordingly.
Reference will now be made to FIG. 4 in showing the attachment between
upper cowling member 24 and lower cowling member 22 through the use of a
rubber seal 50. Upper cowling member 24 is integrally formed with a
stepped ring 52 extending from an inside surface thereof. Seal 50 is
adapted to be attached to stepped ring 52 and to engage a flat 53 formed
as part of rear cowling member 22. At this point, it should be noted that
since upper cowling member 24 is molded of two or more front-to-rear
extending pieces, the front and rear sections 24A and 24B of upper cowling
member 24 can be removed from a mold in a horizontal direction. This
provides an advantage over the prior art arrangement discussed above
wherein, since the longitudinally divided cowling was typically removed
from the mold vertically, a thickened portion 54 was required to enable
the molded cowling to be removed from the mold. In accordance with the
present invention, the thickened portion is not required, since the molded
cowling can be removed horizontally from the mold. This further reduces
the weight of the cowling section and reduces the amount of molding
material required to form the cowling. Again, this minimizes the weight of
upper cowling member 24 so as to ease the installation and removal of
upper cowling member 24 from lower cowling member 22. Furthermore, since
the front and rear cowling sections 24A and 24B can be horizontally
removed from a mold, ribs 34 can be formed around the inside circumference
of upper cowling member 24 in a relatively simple manner.
In the above-described embodiment, an adhesive was used to fix tongue 32 of
rear cowling section 24B in groove 30 of front cowling section 24A. The
embodiment depicted in FIG. 5 is presented to show that various other
fastener means in the art, such as rivet 60 for example, could also be
used to secure front and rear cowling sections 24A, 24B together.
Although described with respect to preferred embodiments of the invention,
it should be readily understood that various changes and/or modifications
can be made to the present invention without departing from the spirit
thereof. For instance, although the invention was described with respect
to upper cowling member 24 being split into two pieces, it would also be
possible to form upper cowling member 24 from three or more pieces, each
of which extend fore and aft with respect to engine 20. It is also
possible to form lower cowling member 22 in a similar manner to that
described with respect to upper cowling member 24. Furthermore, the tongue
and groove type of attachment between front cowling section 24A and rear
cowling section 24B is cited as only exemplary and various other
attachment arrangements could readily be utilized without departing from
the spirit or scope of the invention. Finally, the junction line 25
between front cowling section 24A and rear cowling section 24B need not be
perpendicular to top wall 42 or sidewalls 44 but could be provided at an
angle so as to increase the surface area thereof. In general, the
invention is only intended to be limited by the scope of the following
claims.
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